The present invention is directed to a furnace that provides heated circulation air to an interior comfort space. The invention is more particularly concerned with a technique for mounting the circulation air blower onto a blower shelf of the furnace.
In a force air furnace, the circulation air blower is supported on a horizontal blower shelf beneath the heat exchanger cell. The blower or blowers can typically be a centrifugal blower in which a centrifugal rotor is mounted between blower side plates. The side plates can have flanges that engage flanges or lips on the side of the blower opening formed in the shelf. These lips provide at least some of the support for the blower. Typically, screws are used for mounting to the blower shelf, one on each side plate. These mounting screws pass through mounting flanges on the side plates and into the blower shelf. This arrangement does not provide a great deal of strength for vertical stresses, so it is coon to install shipping blocks around the blower to prevent stress damage during shipping of the furnace. These blocks are necessary to prevent stress cracks in the support shelf and the side plates during shipping. The shipping blocks increase the cost of the furnace, and require additional steps for the installer to remove and dispose of them.
Recently, multi-poise furnaces have been proposed, which can be installed in a normal, upflow configuration, an inverted, downflow configuration, a right flow horizontal configuration or a left flow horizontal configuration, whichever is most suitable to the particular housing unit or other structure. In such multi-poise furnaces the blower should be well supported both horizontally and vertically so that problems do not develop due to stress in operation. However, a conventional furnace, with the blower screwed into the blower shelf above, may not provide sufficient blower support, especially in the horizontal poises.